Question 539538
d = r*t, where d=distance, r=rate, and t=time.
so
t = d/r
.
Truck:
r = 30 mph
d = x miles
t = x/30
.
Car:
r = 35 mph
d = x+5 miles
t = (x+5)/35
.
t = t
so
x/30 = (x+5)/35
.
Cross multiply.
.
35x = 30(x+5)
35x = 30x + 150
5x = 150
x = 30 miles
.
t = 30 miles/30 mph = 1 hr
@ 30 mph it takes 1 hr to travel 30 miles
.
Checking
t = 35 miles/35 mph = 1 hr
@ 35 mph it takes 1 hr to travel 35 miles
.
So, the car will be 5 miles ahead in 1 hr.
.
Done.